The invention resides in a fluidic drive disposed between two compounds which are arranged so as to be movable relative to each other and comprising a hollow body with a fluid admission and a fluid discharge line.
Such drives are used for initiating translatory movements, but also pivot movements or rotational movements mainly in the area of robotics but also prosthetics. They comprise essentially at least one hydraulic or pneumatic drive element disposed between two parts which are arranged movably relative to each other. The drive elements are connected to each of the two parts by at least one force transmission area. Preferably, the drive element comprises a hollow body with an operating fluid supply and discharge line.
DE-AS 23 45 856 discloses a fluidic drive in connection with a manipulator which comprises a bladder disposed at the side of a joint between two opposite force areas of two components such that an expansion of the bladder by filling it with an operating fluid causes the two face areas to be moved apart thereby providing for a pivot or rotational movement of the two components about the pivot joint. A non-resilient sleeve disposed around the bladder limits the volume of the bladder in the radial direction of the sleeve.
The force transmission areas of this drive cover the whole face areas. Since no particular means for the transfer of the drive forces, that is, no particular force guide structures are provided, the operating forces also change during the expansion of the drive. Furthermore, the drive bladder expands in all directions about at the same rate. As a result, not only the force that can be transmitted is limited but also the pivot angle is relatively small and the thickness of the joint including such a drive increases with the expansion of the drive bladder.
It is therefore the object of the present invention to provide a fluidic drive with a guided hollow body which is suitable for the transfer of high forces in connection with large strokes or pivot angles with a relatively small amount of operating fluid. Particularly, the drive should remain relatively slim in any filling state thereof so as to be usable also under tight conditions.